Answer to 'can you simulate it?': the UI now renders on the host.
- pm-ui: shared no_std embedded-graphics drawing (draw_ui), used by BOTH the
firmware and the simulator — single source, no divergence.
- uisim: host crate that draws pm-ui onto a framebuffer and exports a PNG (pure
Rust, no SDL). Confirmed the bring-up pattern renders correctly off-device, so
the black screen is a panel/controller issue, not a draw bug.
- pm-kit: use pm_ui::draw_ui; trim the ST7796 extension init to just unlock + 0xB6
(the gamma/VCOM sent after DISPON likely blanked it); LED solid during init then
slow 1 Hz blink so hung-init / running / reset-loop are distinguishable.
Note: the simulator covers WHAT we draw (layout/colour/logic). It does NOT model
the ST7796 controller's hardware quirks (0xB6 line count, MADCTL scan, SPI init) —
those still need the bench, but that's a one-time bring-up.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
